Biomedical subjects

Xia Li

Publications and source records attributed to Xia Li.

At least 19 recordsLinked to original sources

PubMed2026

Proteomic and phosphoproteomic profiles of time-dependent dynamic changes in LPS-induced macrophage polarization.

The temporal proteomic and phosphoproteomic reprogramming during early M1 macrophage polarization (0-6 h) remains poorly understood. We performed time-resolved proteomic and phosphoproteomic analyses of LPS-stimulated RAW264.7 macrophages at seven time points within 6 h. Time-clustering of differentially expressed molecules revealed two patterns: initial change with partial recovery, and sustained dysregulation. Upregulated proteins and phosphorylation sites were enriched in the Rho GTPase signaling pathway, T-cell receptor signaling pathway, NF-κB cascade, osteoclast differentiation pathway, and antiviral immune pathway. Downregulated pathways were associated with cell cycle regulation, chromatin remodeling, RNA metabolism, and mRNA processing, indicating resource reallocation to prioritize acute inflammatory responses. Kinase-substrate network analysis confirmed the mitogen-activated protein kinase (MAPK), cyclin-dependent kinase (CDK), protein kinase B (AKT), and ribosomal S6 kinase (RSK) families as core upstream phosphorylation regulators. Integrated analysis revealed synergistic and antagonistic relationships between proteomic and phosphoproteomic changes. This study provides a temporal molecular atlas of M1 polarization, delineating inflammatory signaling dynamics and offering a basis for therapeutic target discovery in inflammatory diseases. SIGNIFICANCE: Macrophage M1 polarization is a central event in innate immune defense against pathogenic invasion, yet its dysregulation is a pivotal driver of the onset and progression of a broad spectrum of inflammation-associated disorders, spanning autoimmune diseases, infectious conditions and inflammatory bone diseases, making the dissection of its molecular regulatory mechanisms an urgent research priority in immunology and translational medicine. Dynamic molecular events within 0-6 h after LPS stimulation are critical for initiating and shaping M1 inflammatory activation, yet systematic time-resolved proteomic and phosphoproteomic profiling remains insufficient.In this study, we comprehensively characterized temporal proteome and phosphoproteome changes at seven consecutive time points during macrophage polarization, clarified two distinct dynamic molecular patterns, identified core signaling pathways and key kinase regulators involved in inflammatory reprogramming, and uncovered the leading role of post-translational phosphorylation modifications in initiating polarization. This work delineates the time-series molecular atlas of early macrophage activation, provides novel insights into the temporal regulatory mechanism of inflammatory signaling networks, and lays a solid experimental foundation for exploring new intervention targets and regulatory nodes in clinical translational research.

Lipopolysaccharides↗

PubMed2025

Integrative oral and gut microbiome profiling highlights microbial correlates of complications in type 1 diabetes: a cross-sectional analysis.

BACKGROUND/OBJECTIVE: Chronic vascular complications are the primary threat in long-standing type 1 diabetes (T1D) patients. We examined the associations between oral-gut microbiome dysbiosis and these complications, offering novel insights into therapeutic strategies and underlying mechanisms. METHODS: This cross-sectional study enrolled 75 T1D participants (disease duration ≥ 10 years) and 43 healthy controls who underwent comprehensive clinical assessment, including blood glucose, lipid profile, and complication-related examinations. Fecal and oral rinse samples were collected for shotgun metagenomic sequencing. T1D participants were stratified by the presence of microvascular (retinopathy, nephropathy, or neuropathy) or macrovascular complications separately. Microbial differences across groups were assessed. RESULTS: Significant differences in oral and gut microbiota compositions were observed between T1D participants with and without complications (both microvascular and macrovascular). A core set of 26 gut and 8 oral microbial species was specifically associated with vascular complications. Butyrate-producing gut bacteria (Blautia wexlerae, Anaerobutyricum hallii, Roseburia inulinivorans, A. soehngenii) and specific oral Neisseria species were enriched in T1D without complications individuals, suggesting protective effects against complications. Mediation analysis indicated associations consistent with partial mediation between certain microbial species and the relationships of glycemic control or insulin resistance (HbA1c, glucose risk index, estimated glucose disposal rate) with complication risk. Moreover, potential oral-gut microbiome interconnections were implicated in complication development. Finally, classification models integrating both oral and gut microbial features significantly outperformed models based on either site alone in distinguishing T1D patients with complications. CONCLUSIONS: Distinct oral and gut microbiome features are associated with chronic vascular complications in T1D. These findings highlight the potential of microbiome-targeted strategies for understanding and preventing T1D-related complications.

Humans↗

PubMed2025

Discovery of a novel Betacoronavirus 1, cpCoV, in goats in China: The new risk of cross-species transmission.

Betacoronavirus is a causative agent of respiratory and enteric diseases in humans and animals. Several ruminants are recognized to be intermediate hosts in the transmission of emerging coronaviruses from reservoir hosts to humans. Here, we first report a novel Betacoronavirus isolated from goats suffering from diarrhea in China, putatively named caprine coronavirus (cpCoV). Full-genome characterization and nuclear acid comparisons demonstrated that this virus is an evolutionarily distinct Betacoronavirus belonging to the subgenus Embecovirus and is a Betacoronavirus 1 species. Notably, on phylogenetic trees based on complete genomes and RdRp, S, and N genes, the cpCoVs were grouped into a clade distinct from other Betacoronavirus strains and were closely related to the HKU23- and HKU23-associated coronaviruses. CpCoV possessed a unique genome organization with a truncated NS4a protein and an elongated NS4b protein that showed no significant matches in the GenBank database. The homology of the S and NS4a-4b genes between cpCoV and Embecovirus was less than 95%. Analysis revealed possible recombination events occurred during the evolution of cpCoV and HKU23, and there are striking similarities between the two viruses in evolutionary terms. In addition, cpCoV showed a narrow cell tropism, replicating in human- and bovine-origin cells in vitro, and caused diarrhea and enteric pathologic changes in goats and calves in vivo. We have provided epidemiological, virological, evolutionary, and experimental evidence that cpCoV is a novel etiological agent for enteric disease in goats. Evidently, a spilling-over event might have occurred between ruminants, including goats, camels, cattle, and wild animals. This study highlights the importance of identifying coronavirus diversity and inter-species transmission in ruminants worldwide, broadens our understanding of the ecology of coronaviruses, and aids in the prevention of animal-to-human transmission and outbreaks.

Animals↗

PubMed2025

Broad-spectrum antibacterial and antibiofilm activity of dandelion endophytic bacteria against multidrug-resistant bacteria.

Microbial secondary metabolites have long served as a key source of natural product-based drugs. This study evaluates the antibacterial, antibiofilm, and antioxidant activities of endophytic bacteria derived from dandelion, focusing on their effects against multidrug-resistant (MDR) clinical isolates. In total, 33 endophytic bacteria strains were isolated from Taraxacum ohwianum, representing 15 genera. Among these, 13 exhibited antibacterial activity, with 6 demonstrating efficacy against MDR clinical isolates. The endogenous strain Bacillus velezensis DR8 showed strong antibacterial activity against all three MDR strains tested and exerted inhibitory effects on the biofilm formation and dispersal of methicillin-resistant Staphylococcus aureus. Genome sequencing and antibiotics and secondary metabolite analysis shell analysis revealed that this strain harbors 12 biosynthetic gene clusters (BGCs) associated with secondary metabolite production. Of these, seven BGCs exhibited ≥ 80% similarity to known clusters, suggesting the potential to synthesize surfactin, difficidin, fengycin, bacillaene, macrolactin H, bacilysin, and bacillibactin. Overall, these findings indicate that endophytic bacteria from dandelion are a potential source of antibacterial compounds and biofilm formation inhibitors.

Endophytes↗

PubMed2007

Defining agents' behaviors to simulate complex residential development using multicriteria evaluation.

Cellular automata (CA) have been increasingly used to simulate complex geographical phenomena. These models may have limitations on reflecting individuals' behaviors which should be considered in urban simulation. Agent-based modeling can solve some of the problems in addressing individuals' influences in urban systems. However, there is a general lack of methodology on how to define agents' properties. This paper uses multicriteria evaluation techniques to determine some of the parameters for the agent-based model. Empirical data from GIS are used to define agent's properties. Sensitivity analysis is also carried out to assess the influences of parameters on simulation outcomes. This model has been applied to the simulation of the residential development in a fast growing city, Guangzhou, in south China.

China↗

PubMed2007

Reduced action of polypeptide release factors induces mRNA cleavage and tmRNA tagging at stop codons in Escherichia coli.

Certain C-terminal sequences of nascent peptide cause an efficient protein tagging by tmRNA system at stop codons in Escherichia coli. Here, we demonstrate that both mRNA cleavage and tmRNA tagging occur at UAG stop codon recognized specifically by polypeptide release factor 1 (RF-1) when the activity of RF-1 is reduced by a mutation in the prfA gene without requirement of particular C-terminal sequences of nascent peptide. The tmRNA tagging and mRNA cleavage in the prfA mutant were eliminated when the wild-type RF-1 but not RF-2 was supplied from plasmid. In addition, depletion of either RF-1 or RF-2 induces endonucleolytic cleavage and tmRNA tagging at UAG or UGA stop codons respectively. We conclude that ribosome stalling at the cognate stop codon caused by reduced activity or expression of RF-1 or RF-2 is responsible for mRNA cleavage. The present data along with our previous studies strongly suggest that ribosome stalling leads to endonucleolytic cleavage of mRNA in general resulting in non-stop mRNA and that the 3' end of non-stop mRNA is probably only target for the tmRNA system.

Codon, Terminator↗

PubMed2006

Isolation and characterization of a new bacterium capable of biotransforming cis -epoxysuccinic acid to D(-) -tartaric acid.

A bacterial strain 1-3 capable of enantioselectively hydrolyzing cis-epoxysuccinic acid to D(-)-tartaric acid was isolated from soil. Phenotypic characteristics, Biolog GN test and phylogenetic analysis of strain 1-3 indicated that it belongs to the genus Bordetella. cis-Epoxysuccinic acid could be used as a carbon source and inducer for production of cis-epoxysuccinic acid hydrolase. After the purification of the enzymatic biotransformed product, a colorless and scentless crystal was obtained, which was confirmed to be the tartaric acid with laevorotatory optical rotation by the (1)H nuclear magnetic resonance spectrum and optical rotation analysis.

Bacterial Proteins↗

PubMed2006

Novel mutations found in mitochondrial diabetes in Chinese Han population.

Mitochondria provide cells with most of the energy in the form of ATP. Mutations in mitochondrial DNA (mtDNA) are associated with type 2 diabetes mellitus (T2DM) because ATP plays a critical role in the production and the release of insulin. To systematically determine mutant loci and to investigate their association with T2DM in Chinese Han population, 17 commonly reported mutant loci were screened in 236 cases of T2DM and 240 normal controls by PCR-RFLP, allele-specific PCR (AS-PCR) and DNA sequencing methods. Biological softwares were used to analyze the secondary structure of DNA, RNA and the corresponding proteins for missense mutations. Sixteen mutant loci were detected in total, of which five were novel, GenBank accession nos. were DQ092356, DQ473644 and DQ473645; they were mainly in16S rRNA, ND1 and ND4 gene. There was significant difference between the two groups for ND1 and ND4 genes mutation frequencies (ND1: P=0.001, OR=3.944, 95% CI 1.671-9.306; ND4: P=0.010, OR=5.818, 95% CI 1.275-26.537). No significant association was observed between the two groups for 5178A/C polymorphisms (P=0.418). Our study suggested that T3394C and A12026G might be associated with T2DM in Chinese Han population, and T2DM with mtDNA variant should be considered mitochondrial diabetes.

Adult↗

PubMed2006

A high-resolution map of segmental DNA copy number variation in the mouse genome.

Submicroscopic (less than 2 Mb) segmental DNA copy number changes are a recently recognized source of genetic variability between individuals. The biological consequences of copy number variants (CNVs) are largely undefined. In some cases, CNVs that cause gene dosage effects have been implicated in phenotypic variation. CNVs have been detected in diverse species, including mice and humans. Published studies in mice have been limited by resolution and strain selection. We chose to study 21 well-characterized inbred mouse strains that are the focus of an international effort to measure, catalog, and disseminate phenotype data. We performed comparative genomic hybridization using long oligomer arrays to characterize CNVs in these strains. This technique increased the resolution of CNV detection by more than an order of magnitude over previous methodologies. The CNVs range in size from 21 to 2,002 kb. Clustering strains by CNV profile recapitulates aspects of the known ancestry of these strains. Most of the CNVs (77.5%) contain annotated genes, and many (47.5%) colocalize with previously mapped segmental duplications in the mouse genome. We demonstrate that this technique can identify copy number differences associated with known polymorphic traits. The phenotype of previously uncharacterized strains can be predicted based on their copy number at these loci. Annotation of CNVs in the mouse genome combined with sequence-based analysis provides an important resource that will help define the genetic basis of complex traits.

Animals↗

PubMed2006

Quantitative trait loci for individual adipose depot weights in C57BL/6ByJ x 129P3/J F2 mice.

To understand how genotype influences fat patterning and obesity, we conducted an autosomal genome scan using male and female F(2) hybrids between the C57BL/6ByJ and 129P3/J parental mouse strains. Mice were studied in middle-adulthood and were fed a low-energy, low-fat diet during their lifetime. We measured the weight of the retroperitoneal adipose depot (near the kidney) and the gonadal adipose depot (near the epididymis in males and ovaries in females). An important feature of the analysis was the comparison of linkage results for absolute adipose depot weight and depot weight adjusted for body size, i.e., relative weight. We detected 67 suggestive linkages for six phenotypes, which fell into one of three categories: those specific to absolute but not relative depot weight (Chr 5, 11, and 14), those specific to relative but not absolute depot weight (Chr 9, 15, and 16), and those involving both (Chr 2 and 7). Some quantitative trait loci (QTLs) affected one adipose depot more than another: Retroperitoneal depot weight was linked to Chr 8, 11, 12, and 17, but the linkage effects for the gonadal depot were stronger for Chr 5, 7, and 9. Several linkages were specific to sex; for instance, the absolute weight of gonadal fat was linked to Chromosome 7 in male (LOD = 3.4) but not female mice (LOD = 0.2). Refining obesity as a phenotype may uncover clues about gene function that will assist in positional cloning efforts.

Adipose Tissue↗

PubMed2006

A locus on mouse Chromosome 9 (Adip5) affects the relative weight of the gonadal but not retroperitoneal adipose depot.

To identify the gene or genes on mouse Chromosome 9 that contribute to strain differences in fatness, we conducted an expanded mapping analysis to better define the region where suggestive linkage was found, using the F(2 )generation of an intercross between the C57BL/6ByJ and 129P3/J mouse strains. Six traits were studied: the summed weight of two adipose depots, the weight of each depot, analyzed individually (the gonadal and retroperitoneal depot), and the weight of each depot (summed and individual) relative to body size. We found significant linkage (LOD = 4.6) that accounted for the relative weight of the summed adipose depots, and another for the relative weight of the gonadal (LOD = 5.3) but not retroperitoneal (LOD = 0.9) adipose depot. This linkage is near marker rs30280752 (61.1 Mb, Build 34) and probably is equivalent to the quantitative trait locus (QTL) Adip5. Because the causal gene is unknown, we identified and evaluated several candidates within the confidence interval with functional significance to the body fatness phenotype (Il18, Acat1, Cyp19a1, Crabp1, Man2c1, Neil1, Mpi1, Csk, Lsm16, Adpgk, Bbs4, Hexa, Thsd4, Dpp8, Anxa2, and Lipc). We conclude that the Adip5 locus is specific to the gonadal adipose depot and that a gene or genes near the linkage peak may account for this QTL.

Adipose Tissue↗

PubMed2006

The physical and functional interaction of NDRG2 with MSP58 in cells.

NDRG2, a member of N-Myc downstream regulated gene family, exerts the important functions in cell differentiation and tumor suppression. Although the ectopic expressed Ndrg2 inhibits the proliferation of tumor cells, its intracellular signal transduction pathway is hardly known. Here, we identified MSP58, a 58-kDa microspherule protein, as an interacting partner of human Ndrg2 by using yeast two-hybrid screening. The interaction was confirmed by glutathione S-transferase pull-down assay in vitro and by co-immune-precipitation assay in vivo. The forkhead associated domain of MSP58 is essential for its interaction with Ndrg2. Ndrg2 could co-localize with MSP58 in nuclear of HeLa cell during cell stress. Furthermore, the modulation of Ndrg2 level influences the cell cycle process together with MSP58. In conclusion, the findings offered a novel insight into the physiological roles of Ndrg2.

Animals↗

PubMed2006

Prenatal stress on the kinetic properties of Ca2+ and K+ channels in offspring hippocampal CA3 pyramidal neurons.

Prenatal stress is known to cause neuronal loss and oxidative damage in the hippocampus of offspring rats. To further understand the mechanisms, the present study was undertaken to investigate the effects of prenatal stress on the kinetic properties of high-voltage-activated (HVA) Ca(2+) and K(+) channels in freshly isolated hippocampal CA3 pyramidal neurons of offspring rats. Pregnant rats in the prenatal stress group were exposed to restraint stress on days 14-20 of pregnancy three times daily for 45 min. The patch clamp technique was employed to record HVA Ca(2+) and K(+) channel currents. Prenatal stress significantly increased HVA Ca(2+) channel disturbance including the maximal average HVA calcium peak current amplitude (-576.52+/-7.03 pA in control group and -702.05+/-6.82 pA in prenatal stress group, p<0.01), the maximal average HVA Ca(2+) current density (-40.89+/-0.31 pA/pF in control group and -49.44+/-0.37 pA/pF in prenatal stress group, p<0.01), and the maximal average integral current of the HVA Ca(2+) channel (106.81+/-4.20 nA ms in control group and 133.49+/-4.59 nA ms in prenatal stress group, p<0.01). The current-voltage relationship and conductance--voltage relationship of HVA Ca(2+) channels and potassium channels in offspring CA3 neurons were not affected by prenatal stress. These data suggest that exposure of animals to stressful experience during pregnancy can exert effects on calcium ion channels of offspring hippocampal neurons and that the calcium channel disturbance may play a role in prenatal stress-induced neuronal loss and oxidative damage in offspring brain.

Animals↗

PubMed2006

[Development of a DNA chip screening mitochondrial DNA mutations in patients with diabetes mellitus].

OBJECTIVE: To establish a rapid and precise high-throughput mitochondrial (mt) DNA chip and to investigate the relationship between mtDNA tRNA Leu (UUR) and ND1 gene mutations and diabetes mellitus. METHODS: A wild-type and mutant probes of 28 loci in tRNA Leu (UUR) and ND1 gene were immobilized on the Hybond N + nylon membrane by UV-crosslinking, then the mtDNA chips were used to detect 28 loci mutation in 200 cases of type 2 diabetes mellitus and 210 matched healthy controls. All the mutations were further confirmed by DNA sequencing. Mfold and Antherprot softwares were used to predict the secondary structures of the mutant gene and protein. RESULTS: The mtDNA chip, which could detect 28 loci mutations, was successfully developed. In diabetic group, there were 2 (1.0%) cases of T3 290C mutation, 6 (3.0%) of G3 316A (Ala-->Thr) mutation, 5 (2.5%) of T 3 394C (Tyr-->His) mutation, 1 (0.5%) of T3 593 C (Val-->Ala) mutation, 1 (0.5%) of A3 606G (Leu-->Leu) mutation, 8 (4.0%) of A4 164G (Met-->Met) mutation, 2 (1.0%) of T4 216C (Met-->His) mutation. In the controls, 1 (0.5%) carrier of G3 316A mutation and 5 (2.4%) carriers of A4 164G mutation were found. There was significant difference between two groups for T3 394C mutation frequencies (P = 0.027). The secondary structures of the mutant proteins of G3 316A, T3 394C, T3 593C and T4 216C mutations were all different from those of the wild-types'. CONCLUSION: mtDNA chip is a rapid and reliable high-throughput method for mutations detection, and T3 394C mutation in ND1 gene might contribute to the pathogenesis of mitochondrial diabetes.

Adult↗

PubMed2006

The CD4(+) regulatory T-cells is decreased in adults with latent autoimmune diabetes.

The latent autoimmune diabetes in adults (LADA) is a subgroup of type 1 diabetes, which procession of autoimmune destruction of beta-cells was slower than classic type 1 diabetes. To investigate the pathogenesis of LADA, we examined the lymphocyte subsets including the CD4(+)CD25(+) T-cells in 60 LADA patients and 30 patients of type 2 diabetes and 30 healthy individuals by FACS. And we compared the expression of FOXP3 mRNA in CD4(+) T-cell between 10 patients of LADA and 10 matched healthy individuals by real time PCR. The percent of CD4(+)CD25(+) T-cells were higher (11.89+/-4.96% versus 8.16+/-3.65%, P<0.01), and the percent CD8(+) T-cells elevated (24.58+/-6.80% versus 19.39+/-7.12, P<0.01) in LADA patients than healthy individuals. While the expression of FOXP3 mRNA in CD4(+) T-cell was markedly decreased in LADA patients (0.52-fold, n=10, P=0.004) compared with normal subjects. In addition, the percent of CD8(+) T-cells related with GAD-Ab titers in LADA patients (r=0.292, P=0.03). Our results showed that there were cellular immune disorder and decreased CD4(+) regulatory T-cells in LADA patients. The adoptive transfer regulatory T-cells seem to be a potential therapeutics for LADA.

Adult↗

PubMed2006

Bioactive galactose-branched polyelectrolyte multilayers and microcapsules: self-assembly, characterization, and biospecific lectin adsorption.

We describe the fabrication of multilayers and microcapsules with biologically designed targeting activity using chemoenzymatic synthesized carbohydrate-branched polyelectrolytes. A novel cationic d-galactose-branched copolymer [poly(vinyl galactose ester-co-methacryloxyethyl trimethylammonium chloride), PGEDMC] is alternated with poly(styrene sulfonate) (PSS) to form thin multifilms by the layer-by-layer (LbL) technique on such different solid surfaces as quartz slides, poly(ethylene terephthalate) (PET) films, silicon wafers, and polystyrene (PS) microparticles. The experimental protocols were first optimized on flat, smooth silica substrates using UV-vis, contact angle, and atomic force microscopy (AFM) measurements. The film properties of PGEDMC/PSS multilayers are modified by varying polyelectrolyte concentration, ionic strength, and counteranion types. Hollow capsules were formed after the removal of colloidal templates; transmission (TEM) and scanning (SEM) electron microscopy were used to verify the LbL process integrity. PGEDMC/PSS planar films and capsules carrying beta-galactose as recognition signals have specific recognition abilities with peanut agglutinin (PNA) lectin rather than concanavalin A (Con A) lectin observed by fluorescence spectroscopy.

Adsorption↗

PubMed2006

[Decrease of FOXP3 mRNA in CD4+ T cells in latent autoimmune diabetes in adult].

OBJECTIVE: To study the percentage of peripheral blood CD4(+)CD25(+) T cells and the expression of FOXP3 mRNA in the patients with latent autoimmune diabetes in adult (LADA). METHODS: Fresh peripheral blood samples were obtained from 60 patients with LADA, 30 patients with type 2 diabetes and 30 age- and sex-matched matched healthy nondiabetic control subjects without diabetic family history. Two-color staining (anti-CD4, anti-CD25, anti-CD3, and anti-CD8) flow cytometric analysis was employed to measure the CD4(+)CD25(+) T cells. The CD4 positive human cells were isolated with immunomagnetic beads, and then real time-PCR was used to test the expression of FOXP3 mRNA in the CD4(+) T cells. RESULTS: In the LADA group, the percentage of CD4(+)CD25(+) T cells was 4.1 +/- 1.9, significantly higher than that of the normal control group (2.8 +/- 1.5, P < 0.01), the ratio of CD4(+)CD25(+) to the CD4(+) T cells was 11.9 +/- 5.0, significantly higher than that of the normal control group (8.2 +/- 3.7, P < 0.01), the percentage CD8(+) T cells was 24.6 +/- 6.8, significantly higher than that of the normal control group (19.4 +/- 7.1, P < 0.01) and the CD4(+)/CD8(+) ratio was 1.5 +/- 0.5, significantly lower (1.9 +/- 0.6, P < 0.01). The expression of FOXP3 mRNA in CD4(+) T cells of the LADA group was 0.52 time that of the control group (P < 0.01). The CD4(+)/CD8(+) ratio of LADA group was significantly lower that of the type 2 diabetes group (1.8 +/- 0.8, P < 0.05), however, the other results were not significantly different between these 2 groups. The percentage of was positively correlated with the titer of glutamic acid decarboxylase antibody (GADA) (r = 0.292, P < 0.05). CONCLUSION: Though the percentage of CD4(+)CD25(+) T cells and the level of CD25 expression in CD4(+) T cells are elevated, the expression of FOXP3 mRNA in CD4(+) T cells is lower. in the patients with LADA. The regulatory T cells may have defective suppressor function in patients with LADA.

Adult↗

PubMed2006

Expression and characterization of a thermostable sarcosine oxidase (SOX) from Bacillus sp. in Escherichia coli.

A heat-stable sarcosine oxidase produced by Bacillus sp. BSD-8 (SOX) had been studied and its complete gene sequence, which contained 1,164 bp nucleotides and encoded a protein of 387 amino acids, was obtained by DNA Walking method. The sox gene was cloned and functionally overexpressed in E. coli and the recombinant SOX (rSOX) was purified to homogeneity, its properties was studied and compared with the wild type of SOX. The rSOX as well as SOX was stable at 60 degrees C and at pH 7.0 approximately 10.0, respectively. The optimal temperature for this enzyme was 60 degrees C and at pH 8.5, it showed its highest activity. The Km and Kcat of the enzyme was 3.1 mM and 20.3/s, respectively. The difference between the properties of the SOX and rSOX was that the SOX contained noncovalent FAD, whereas the rSOX contained covalent FAD. The study also showed that an increased number of alanine residues in the rSOX might have some contribution in the enzymatic thermostability.

Amino Acid Sequence↗